This invention relates to a work apparatus for a work on a wall surface of a structure and, more particularly, to a work apparatus capable of minimizing a portion of the structure covered by a protecting net so that a work at an elevated location can be done by covering only a portion of the structure on which the work is carried out by a working platform of a moving scaffold or the like appratus which can move vertically and horizontally along the outer wall surface of the structure.
For performing works at elevated locations such as construction and repair of a wall surface of buildings, ships, power stations, tanks, chimneys and bridges safely and efficiently, work apparati for elevated places such as moving scaffolds and unmanned machines are often used instead of conventional provisional scaffolds.
When a moving scaffold which is one of such work apparati used at elevated locations is applied to a building, for example, the moving scaffold is hung from a pair of mounting frames secured to a parapet on the roof of the building by means of wires and is moved vertically by means of winders mounted on the moving scaffold.
In such moving scaffold, work in the vertical direction can be peformed efficiently but work performed on a wall portion outside of the width of the moving scaffold can only be performed within the reach of a workman's hand. It is therefore necessary to shift the position of the moving scaffold horizontally along the wall surface by dismounting the mounting frames from one place and mounting them on another place in the parapet on the roof. As the area of work in the horizontal direction increases, the number of such remounting of the moving scaffold increases with a resulting decrease in the work efficiency.
For obviating such remounting of the moving scaffold, there has been proposed an apparatus in which a running rail is permanently provided on a roof of a building for trolleys to run along the running rail and a moving scaffold is hung from these trolleys by means of wires. There has also been proposed an appratus, as in Japanese Laid Open Patent Publication No. 61-185848, in which a horizontal rail is provisionally mounted on the roof of a building through mounting frames and a moving scaffold is hung from trolleys slidably mounted on the horizontal rail. Work efficiently can be increased by using a work apparatus such as a moving scaffold which can move not only vertically but also horizontally as described above.
In performing such work on a wall surface at an elevated location, a protecting net is normally provided over all of the wall surface on which the work is to be performed.
Since the entire wall surface of the structure is covered by the protecting net regardless of the position of the moving scaffold, considerable time is required for mounting and dismounting the protective net. Besides, a great deal of material is required for providing the protective net over the entire wall surface. Furthermore, safety measures must be taken for ensuring safety in hanging a heavy material for providing the protective net which results in further increase in the cost.
Moreover, in a structure such as a building which is being used, it is a problem that even a portion of a building which is irrelevant to the work is covered until the work is finished.
The same problems arise in work apparati used for work at elevated locations other than moving scaffolds.
It is, therefore, an object of the invention to provide a work apparatus for a work on a wall surface of a structure capable of moving vertically and horizontally and capable of performing a work while covering only a portion of the wall surface which is necessary for the work with a protecting net.